Method for selective isolation and purification of nucleic acids

Abstract

The present invention relates to a gentle method for isolating and purifying nucleic acids from a biological cell comprising sample comprising at least DNA, RNA, and proteins, comprising at least the steps of 1. mixing the sample with a lysis buffer, 2. incubating the sample at a temperature within a range between 45° C. and 59° C. to obtain DNA as well as RNA or within a range between 60° C. and 70° C., to obtain DNA essentially free of RNA and 3. separating the nucleic acids from any contaminants.

1 .- 6 . (canceled) 
     
     
         7 . A method for isolating and purifying nucleic acids from a cell comprising biological sample comprising at least DNA, RNA, and proteins, comprising:
 (a) mixing the sample with a lysis buffer;   (b) incubating the sample at a temperature
 (i) within a range between 45° C. and 59° C. to obtain DNA as well as RNA, or 
 (ii) within a range between 60° C. and 70° C. to obtain DNA essentially free of RNA; and 
   (c) separating the nucleic acids essentially from any contaminants.   
     
     
         8 . The method according to  claim 7 , wherein incubating in step (b) is carried out for at least 5 min. 
     
     
         9 . The method according to  claim 7 , wherein incubating in step (b) is carried out for 10 to 80 min. 
     
     
         10 . The method according to  claim 7 , wherein incubating in step (b) is carried out for 15 to 60 min. 
     
     
         11 . The method according to  claim 7 , wherein the temperature range is from 50° C. to 58° C. for isolating a combination of DNA and RNA. 
     
     
         12 . The method according to  claim 7 , wherein the temperature range is from 55° C. to 57° C. for isolating a combination of DNA and RNA. 
     
     
         13 . The method according to  claim 7 , wherein the temperature range is from 61° C. to 65° C. for isolating DNA that is essentially free of RNA. 
     
     
         14 . The method according to  claim 7 , wherein the temperature range is from 61° C. to 63° C. for isolating DNA that is essentially free of RNA. 
     
     
         15 . The method according to  claim 7 , wherein the lysis buffer comprises an anionic surfactant. 
     
     
         16 . The method according to  claim 7 , wherein the lysis buffer is essentially free of a chelating or complexing agent. 
     
     
         17 . The method according to  claim 15 , wherein the lysis buffer has a pH in the range of pH 8 to 9. 
     
     
         18 . The method according to  claim 16 , wherein the lysis buffer has a pH in the range of pH 8 to 9.